A major problem in agricultural technology is the improvement and stabilization of production. For this purpose, many plant growth promoters have already been developed. However, the effects of conventional promoters are limited, and the need remains for an agent that more efficiently causes stable effects For example, gibberellin is a plant hormone and is applied as a plant growth promoter to a large number of crops, yet is limited in effect as well as in the range of applicable crops.
It is also known that combinations of gibberellin and natural abscisic acid, are possible to promote plant growth such as promotion of thickening and growth of crops, promotion of elongation of cedars, promotion of flowering etc. However, the concentration of each chemical necessary to yield an effect is high, so development of more superior plant growth promoters has been desired (Japanese Laid-Open Patent Publication No. 139912/1993; Japanese Laid-Open Patent Publication No. 172110/1994; Gifu University, Local Joint Research Center, Report No. 5, pp. 81-86, May 1995).